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r (Page 4) MINE ID X OR PROSPECTING ID k M-77-300 INSPECTION DATE 9/22/99 INSPECTOR'S INITIALS ACS 4 to 6 inches topsoil, this area will undergo seedbed preparation and will be re~~egetated using the plant species listed in this exhibit. Since these statements in the reclamation plan cannot be readily applied to the reclamation of the parking lot fill that slopes down to the creek, reclamation of this outslope should be specifically addressed. The technical revision should also include a statement that any oil cw~taminated soil in the parking lot will be collected and properly disposed of off-site or analyz ecl and shown to be suitable for onsite disposal. 2. It is likely that the access road up Ralston Creek will remain in some form in the reclaimed area. Through portions of the mine site the road is immediately adjacent to the creek and limits the development of the riparian area to the creek bank. It was agreed that during zeclartation Cotter would relocate the road to the west where feasible and establish vegetation on the overb~cnk where the road is currently located. In particular, the reach from the guard shack location to the parking lot would benefit from the implementation of such a plan, and the road relocation could be easily accomplished. The west and east mine dumps were inspected. The proposal included in technical revision TR-09 for dump reclamation is to eliminate the riprap requirement specified in the 1983 reclamation plan and to relocate dump rock from the north ends of the east and west piles. The rationale f:or this change is based on the waste rock pile footprints being much smaller today than was envisioned in the 1983 plan. A1[hough Cotter is currently mining and shipping ore from the Schwartzwalder Mine, the ore sorter that produced reject rock comprising about 50 percenC of the material delivered to the dumps has been decommissioned. Under the current and near term mining plan, no additional development rock will be placed on the dumps. If the dumps will be enlarged in the future, Cotter will revi:;e the reclamation plan accordingly (see letter from Cotter Corporation dated June 19, 1999 in TR-04 f.ile). By removing the north end of the dumps, the configurations proposed in the TR-04 application wi1L not erode during a 50-year flood on Ralston Creek. The Division's adequacy letter dated May 19, 1999 requires a demonstration or revised design demonstrating dump stability during the 100-year f7 ood. The following observations were made during the inspection of the dumps. • The west dump outslope is at the angle of repose, and the north lobe of the dumF~ has not yet been relocated. The approximate section of the dump to be removed under the TR-04 Flan was described by Cotter personnel, and the mechanics of earthmoving necessary to cut the outslope of the dump to 2:1 were discussed. • The reclamation grading work on the east dump has been largely completed. The north tip of the dump has been removed to the lines and grade specified in the TR-04 application. The area from which the waste rock has been removed has not yet been seeded. Most of the dump outsl o)~e has been graded to 2:1. There is an access bench cut into the approximate vertical center of the east dump outslope. The configuration of this bench in the final reclaimed topography was discussed. It is the Division's opinion that the bench should remain as it will enhance the bulk stability of the dump by reducing the overall outslope angle and will reduce the flow path of any r~~noff flowing down the dump face. The bench should be graded to carry water off the dump to the north and south, with a divide in the center. It should be noted that the reclamation plan approved in 1983 encouraged the establishment of terraces in the dump outslopes where feasible. • An access road along the interior edge of the dump was inspected. This road may remain in an appropriately modified form in the reclaimed topography. The road will provide access to the top of the dump for revegetation monitoring and maintenance and for rill and gully maintenance. The road will also provide access to the east dump energy dissipater discussed below f:or inspection and maintenance. To remain as a reclaimed feature, the road cuts must be graded to 2:1 and appropriately sized and spaced water bars installed. Once the dump revegetation work is completed, the road should be topsoiled and seeded, and once the access to the top of the jump is no longer needed, the road should be disabled through placement of a berm at the access point. The proposed energy dissipater location at the confluence of a steep gulch with th~=_ top of the east dump was inspected. The location where the gulch intersects the dump had been over e::cavated to expose the underlying soils and bedrock. There was a small flow of water in the excavation. The design of the energy dissipater was discussed. The design will include the installation of s relatively fine grained bedding over the dump rock, installation and anchoring of a geosynthetic clay liner, and